Conventional slide projectors have been known in the patent literature and on the marketplace for many years. Such projectors employ a powerful beam of light to project a real image of a slide onto a diffuse light reflecting surface, such as a screen or uniform wall surface.
With the widespread introduction of color television receivers into everyday use, it has been proposed to use a television receiver for display of slides, thereby obviating the need for a special screen or suitable reflecting surface for projection thereon and for darkening the room during the slide presentation.
A proposed system of this type is described in U.S. Pat. No. 4,331,979 wherein a still image produced by a slide is converted into a television signal by a solid state imager (CCD) device which is scanned across the image. Since frame storage is required for each color, a large amount of memory capacity is required, rendering the apparatus quite expensive and not suitable for use as a mass-marketed domestic appliance.
An alternative system of this type was described in U.S. Pat. No. 3,566,012 which employs a flying spot scanner which operates in conjunction with dichroic mirrors and suitable filters to separate the information derived from the scan into its representative color components which are then transmitted to the electrodes of the color cathode ray tube. This system is also complex and delicate due to the presence of the scanning apparatus and also due to the color separation employed thereby.
U.S. Pat. No. 3,770,882 describes a video reproduction system for photographic and other images wherein a television picture tube upon which the image is displayed is utilized as a flying spot scanner to emit pulsating beams to sample the image. A photo-detector is positioned to receive the light from the television tube which passes through or is reflected from the image. This system is no less complex or costly than those described hereinabove.